The oppressive weather made the work difficult for them.

The correct answer is C. unbearable.

The word "oppressive" means "very severe or harsh". In the context of the question, the oppressive weather is making the work difficult for them because it is very severe or harsh. The other options are not as accurate descriptions of the weather.

• Turbulent: This word means "characterized by wild and violent movements". This does not accurately describe the weather in the question, as it is not necessarily wild or violent.
• Disappointing: This word means "causing disappointment". This does not accurately describe the weather in the question, as it is not necessarily disappointing.
• Cold: This word means "having or feeling a low temperature". This does not accurately describe the weather in the question, as it is not necessarily cold.